implement ray casting events

openVulkanoCpp/Scene/Camera.cpp

@@ -0,0 +1,68 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "Camera.hpp"
+#include "Scene/Scene.hpp"
+#include "Scene/SimpleDrawable.hpp"
+#include "Scene/Geometry.hpp"
+#include "Scene/Shader/Shader.hpp"
+#include "Scene/TextDrawable.hpp"
+#include "Scene/Prefabs/LabelDrawable.hpp"
+#include "Scene/Ray.hpp"
+#include "Scene/TextDrawable.hpp"
+
+namespace OpenVulkano::Scene
+{
+
+	std::optional<DrawableRayHit> PerspectiveCamera::CastRay(const Math::Vector2i& xy) const
+	{
+		using namespace Math::Utils;
+
+		auto scene = GetScene();
+
+		// nds
+		float ndsX = (2.f * xy.x) / m_width - 1.0f;
+		float ndsY = (2.f * xy.y) / m_height - 1.0f;
+
+		Math::Vector4f rayClip = { ndsX, ndsY, 0, 1.f };
+
+		Math::Vector4f rayEye = inverse(m_projection) * rayClip;
+		rayEye.z = -1;
+		rayEye.a = 0;
+
+		Math::Vector3f rayWorld = normalize(inverse(m_view) * rayEye);
+		
+		std::optional<DrawableRayHit> res;
+		for (Drawable* d: scene->rayHittableDrawables)
+		{
+			const auto& m = d->GetNodes()[0]->GetWorldMatrix();
+			const Math::Vector3f rayLocalDir = normalize(inverse(m) * Math::Vector4f(rayWorld, 0));
+			const Math::Vector4f rayLocalPos = inverse(m) * m_camPosition;
+			const Ray ray(rayLocalPos, rayLocalDir);
+			if (auto hit = d->Intersect(ray))
+			{
+				// choose the closest one
+				if (!res || (hit->distance < res->distance))
+				{
+					res = hit;
+					res->drawable = d;
+				}
+			}
+		}
+		if (res)
+		{
+			if (SimpleDrawable* sd = dynamic_cast<SimpleDrawable*>(res->drawable))
+			{
+				Logger::APP->info("Ray intersects object {}", sd->GetMesh()->name);
+			}
+			else if (LabelDrawable* sd = dynamic_cast<LabelDrawable*>(res->drawable))
+			{
+				Logger::APP->info("Ray intersects label {}", sd->GetTexts().front().GetText());
+			}
+		}
+		return res;
+	}
+}